Electrostrictive effect for active control of surface plasmon signals

Real-time surface plasmon modulation was achieved by electrically varying the pitch of a nanoscale surface relief diffraction grating inscribed on an azobenzene thin film covered with a layer of silver. The azobenzene film was spin coated on an electrostrictive Lead Lanthanum Zirconate Titanate (PLZT) ceramic substrate and a combination of DC bias and AC electric fields were applied longitudinally on the PLZT ceramic causing a change in the grating's pitch as well as the surface plasmon's resonance wavelength. This method permits extremely accurate control of the surface plasmon wavelength for tunable optics applications.